Predicted to enable signaling receptor activity. Involved in central nervous system maturation and positive regulation of Wnt signaling pathway. Located in endosome membrane and lysosomal membrane. Is expressed in several structures, including decidua; extraembryonic component; forebrain; neural retina; and renal cortex. Human ortholog(s) of this gene implicated in X-linked parkinsonism-spasticity syndrome; congenital disorder of glycosylation type II; and syndromic X-linked intellectual disability Hedera type. Orthologous to human ATP6AP2 (ATPase H+ transporting accessory protein 2). [provided by Alliance of Genome Resources, Apr 2022]